By Alice Treloar
Are you thinner than you thought?
Tall poppy syndrome literally strikes again. A number-crunching academic from Oxford University, Mathematician Professor Nick Trefethen, believes the formula used to calculate body mass index (BMI) – an estimation of how much body fat you’re carrying – is flawed. And it favours the tall.
His theory? The current formulation doesn’t take into account how much natural bulk taller people have, making the Nicole Kidman's of the world too fat and the vertically challenged too thin.
The current BMI calculation is found by dividing weight in kilograms by height in metres squared. If the answer falls:
Under 18 – you’re very underweight and possibly malnourished
Under 20 – you’re underweight and could afford to gain a little weight
20 to 25 - you have a healthy weight range for young and middle-aged adults
26 to 30 – you’re overweight
Over 30 – you’re obese
But Trefethen’s new method suggests multiplying weight in kilograms by 1.3, to allow for more bulk scope. The answer is then divided by a person’s height to the power of 2.5.
“BMI divides the weight by too large a number for short people and too small a number for tall people. So short people are mislead into thinking that they are thinner than they are, and tall people are mislead into thinking they are fatter,” Professor Trefethen said.
In layman’s terms, this could mean that tall people clear themselves from the overweight or obese category, while vertically challenged individuals could enter the danger zone.
But for the Short Sally’s of the world, don’t fret. Trefethen doesn’t expect his new blueprint to be adopted by health professionals as gospel but does call for health professionals to justify the current calculations.